Libvirtd only support hooks when the daemon is started. Hooks cannot be
loaded when the daemon is already running. So, to load a hook you need to
restart the service everytime. Now, the inotify support enables the option
of create a hook and run it even if libvirtd was started.
Cc: Carlos Castilho <ccasti@xxxxxxxxxx>
Signed-off-by: Julio Faracco <jcfaracco@xxxxxxxxx>
---
daemon/libvirtd.c | 1 +
src/libvirt_private.syms | 1 +
src/util/virhook.c | 165 ++++++++++++++++++++++++++++++++++++++++++++++-
src/util/virhook.h | 10 +++
4 files changed, 175 insertions(+), 2 deletions(-)
diff --git a/daemon/libvirtd.c b/daemon/libvirtd.c
index 95c1b1c..56175d1 100644
--- a/daemon/libvirtd.c
+++ b/daemon/libvirtd.c
@@ -1622,6 +1622,7 @@ int main(int argc, char **argv) {
0, "shutdown", NULL, NULL);
cleanup:
+ virHookCleanUp();
virNetlinkEventServiceStopAll();
virObjectUnref(remoteProgram);
virObjectUnref(lxcProgram);
diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms
index 6a77e46..c8ad816 100644
--- a/src/libvirt_private.syms
+++ b/src/libvirt_private.syms
@@ -1648,6 +1648,7 @@ virHashValueFree;
virHookCall;
virHookInitialize;
virHookPresent;
+virHookCleanUp;
# util/virhostdev.h
diff --git a/src/util/virhook.c b/src/util/virhook.c
index facd74a..d5fc928 100644
--- a/src/util/virhook.c
+++ b/src/util/virhook.c
@@ -26,6 +26,7 @@
#include <sys/types.h>
#include <sys/wait.h>
#include <sys/stat.h>
+#include <sys/inotify.h>
#include <unistd.h>
#include <stdlib.h>
#include <stdio.h>
@@ -45,6 +46,10 @@ VIR_LOG_INIT("util.hook");
#define LIBVIRT_HOOK_DIR SYSCONFDIR "/libvirt/hooks"
+#define virHookInstall(driver) virHooksFound |= (1 << driver);
+
+#define virHookUninstall(driver) virHooksFound ^= (1 << driver);
+
VIR_ENUM_DECL(virHookDriver)
VIR_ENUM_DECL(virHookDaemonOp)
VIR_ENUM_DECL(virHookSubop)
@@ -109,6 +114,8 @@ VIR_ENUM_IMPL(virHookLibxlOp, VIR_HOOK_LIBXL_OP_LAST,
static int virHooksFound = -1;
+static virHookInotifyPtr virHooksInotify = NULL;
+
/**
* virHookCheck:
* @driver: the driver name "daemon", "qemu", "lxc"...
@@ -153,6 +160,121 @@ virHookCheck(int no, const char *driver)
return ret;
}
+/**
+ * virHookInotifyEvent:
+ * @fd: inotify file descriptor.
+ *
+ * Identifies file events at libvirt's hook directory.
+ * Install or uninstall hooks on demand. Acording file manipulation.
+ */
+static void
+virHookInotifyEvent(int watch ATTRIBUTE_UNUSED,
+ int fd,
+ int events ATTRIBUTE_UNUSED,
+ void *data ATTRIBUTE_UNUSED)
+{
+ char buf[1024];
+ struct inotify_event *e;
+ int got;
+ int driver;
+ char *tmp, *name;
+
+ VIR_DEBUG("inotify event in virHookInotify()");
+
+reread:
+ got = read(fd, buf, sizeof(buf));
+ if (got == -1) {
+ if (errno == EINTR)
+ goto reread;
+ return;
+ }
+
+ tmp = buf;
+ while (got) {
+ if (got < sizeof(struct inotify_event))
+ return;
+
+ VIR_WARNINGS_NO_CAST_ALIGN
+ e = (struct inotify_event *)tmp;
+ VIR_WARNINGS_RESET
+
+ tmp += sizeof(struct inotify_event);
+ got -= sizeof(struct inotify_event);
+
+ if (got < e->len)
+ return;
+
+ tmp += e->len;
+ got -= e->len;
+
+ name = (char *)&(e->name);
+
+ /* Removing hook file. */
+ if (e->mask & (IN_DELETE | IN_MOVED_FROM)) {
+ if ((driver = virHookDriverTypeFromString(name)) < 0) {
+ VIR_DEBUG("Invalid hook name for %s", name);
+ return;
+ }
+
+ virHookUninstall(driver);
+ }
+
+ /* Creating hook file. */
+ if (e->mask & (IN_CREATE | IN_CLOSE_WRITE | IN_MOVED_TO)) {
+ if ((driver = virHookDriverTypeFromString(name)) < 0) {
+ VIR_DEBUG("Invalid hook name for %s", name);
+ return;
+ }
+
+ virHookInstall(driver);
+ }
+ }
+}
+
+/**
+ * virHookInotifyInit:
+ *
+ * Initialize inotify hooks support.
+ * Enable hooks installation on demand.
+ *
+ * Returns 0 if inotify was successfully installed, -1 in case of failure.
+ */
+static int
+virHookInotifyInit(void) {
+
+ if (VIR_ALLOC(virHooksInotify) < 0)
+ goto error;
+
+ if ((virHooksInotify->inotifyFD = inotify_init()) < 0) {
+ virReportError(VIR_ERR_INTERNAL_ERROR, "%s", _("cannot initialize inotify"));
+ goto error;
+ }
+
+ if ((virHooksInotify->inotifyWatch =
+ inotify_add_watch(virHooksInotify->inotifyFD,
+ LIBVIRT_HOOK_DIR,
+ IN_CREATE | IN_MODIFY | IN_DELETE)) < 0) {
+ virReportSystemError(errno, _("Failed to create inotify watch on %s"),
+ LIBVIRT_HOOK_DIR);
+ goto error;
+ }
+
+ if ((virHooksInotify->inotifyHandler =
+ virEventAddHandle(virHooksInotify->inotifyFD,
+ VIR_EVENT_HANDLE_READABLE,
+ virHookInotifyEvent, NULL, NULL)) < 0) {
+ VIR_DEBUG("Failed to add inotify handle in virHook.");
+ goto error;
+ }
+
+ return 0;
+
+error:
+ virHookCleanUp();
+ return -1;
+}
+
+
/*
* virHookInitialize:
*
@@ -174,10 +296,14 @@ virHookInitialize(void)
return -1;
if (res == 1) {
- virHooksFound |= (1 << i);
+ virHookInstall(i);
ret++;
}
}
+
+ if (virHookInotifyInit() < 0)
+ VIR_INFO("Disabling hooks inotify support.");
+
return ret;
}
@@ -309,7 +435,12 @@ virHookCall(int driver,
if (output)
virCommandSetOutputBuffer(cmd, output);
- ret = virCommandRun(cmd, NULL);
+ ret = virHookCheck(driver, virHookDriverTypeToString(driver));
+
+ if (ret > 0) {
+ ret = virCommandRun(cmd, NULL);
+ }
+
if (ret < 0) {
/* Convert INTERNAL_ERROR into known error. */
virReportError(VIR_ERR_HOOK_SCRIPT_FAILED, "%s",
@@ -322,3 +453,33 @@ virHookCall(int driver,
return ret;
}
+
+/**
+ * virHookCall:
+ *
+ * Release all structures and data used in virhooks.
+ *
+ * Returns: 0 if the execution succeeded
+ */
+int
+virHookCleanUp(void)
+{
+ if (!virHooksInotify)
+ return -1;
+
+ if ((virHooksInotify->inotifyFD >= 0) &&
+ (virHooksInotify->inotifyWatch >= 0))
+ if (inotify_rm_watch(virHooksInotify->inotifyFD,
+ virHooksInotify->inotifyWatch) < 0)
+ virReportError(VIR_ERR_INTERNAL_ERROR, "%s", _("Cannot remove inotify watcher."));
+
+ if (virHooksInotify->inotifyHandler >= 0)
+ virEventRemoveHandle(virHooksInotify->inotifyHandler);
+
+ VIR_FORCE_CLOSE(virHooksInotify->inotifyFD);
+ VIR_FREE(virHooksInotify);
+
+ virHooksFound = -1;
+
+ return 0;
+}
diff --git a/src/util/virhook.h b/src/util/virhook.h
index 205249c..47a32c7 100644
--- a/src/util/virhook.h
+++ b/src/util/virhook.h
@@ -100,6 +100,14 @@ typedef enum {
VIR_HOOK_LIBXL_OP_LAST,
} virHookLibxlOpType;
+struct _virHookInotify {
+ int inotifyFD;
+ int inotifyWatch;
+ int inotifyHandler;
+};
+
+typedef struct _virHookInotify *virHookInotifyPtr;
+
int virHookInitialize(void);
int virHookPresent(int driver);
@@ -107,4 +115,6 @@ int virHookPresent(int driver);
int virHookCall(int driver, const char *id, int op, int sub_op,
const char *extra, const char *input, char **output);
+int virHookCleanUp(void);
+
#endif /* __VIR_HOOKS_H__ */
--
2.7.4
--
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